• by Erik Sass , Staff Writer @eriksass1, December 12, 2016

Twitter has blocked access to another social media analytics company due to concerns over the information being used for police surveillance of protesters. This time Twitter is cutting off Media Sonar, a Canadian firm that had been providing social media monitoring and analytics to police departments in the United States, according to The Daily Dot, which first reported the news.

Media Sonar had helped police departments south of the border monitor Twitter for words that might be tipoffs to a variety of criminal activity, including drug deals and prostitution – but it also flagged tweets using keywords like “policebrutality” and “justiceformike,” referring to the shooting death of teenager Michael Brown in 2014.

These and similar keywords, with no discernible connection to crime, have been used by protesters from the Black Lives Matter movement, and their inclusion in Media Sonar’s monitoring program seems to suggest that police departments were also using the service to track activists and block or disrupt protests.

As noted previously, Twitter has already blocked access to user data for several other analytics firms over concerns about police surveillance, including Geofeedia and Snaptrends; Geofeedia subsequently cut its staff and announced a strategic repositioning of the company following Twitter’s termination of access.

Local governments across the U.S. have bought software to monitor social media, many of them for security purposes, according to a recent survey of procurements by county and city governments conducted by the Brennan Center for Justice at New York University.

Overall, the survey counted 151 cities, counties, police departments, and other local government bodies that have made purchases of more than $10,000 for social media monitoring. Most procurements were for one of eight different social media monitoring products: Geofeedia, Media Sonar, Snaptrends, Dataminr, DigitalStakeout, PATHAR, Meltwater and Babel Street.